Process of forming asphalt cement ply board



May 23, 1933. s. .1. BLUM 1,910,671

PROCESS OF FORMING ASPHALT CEMENT PLY BOARD Filed July 1950 INVENTOR 856717 TIBZZM)? mwm ATTORNEY/S Patented May 23, 1933 um'rso sures PATENT OFFICE SIDNEY .l'. BLUE, OF DETROIT, MICHIGAN, ABSIGNOR TO ARVEY CORPORATION, OF DETROIT, IICHIGAN, A CORPORATION OF ILLINOIS EBOGISS F FORMING- .ASPEALT CEMENT PIlY BOARD Application filed July 7, 1930. Serial No. 466,242.

The invention relates to the manufacture of ply hoard suitable for use for various purposes such as the forming of the lining or inner panels of automobile hodies. It is t the object of the invention to obtain a product which has the desired thickness and strength and which is free from any tendency to warp or distort either before. or

after its application.

In the present state of the art paper board has been manufactured in which asphaltum is used as the hinder for the iiloers. This hoard is not of suilicient thickness or strength for use as liner panels and to in-.

novel process and product as hereinafter set.

ziorth.

In the drawing:

Figure l is a diagrammatic longitudinal 33 section showing the manner of treating an assenihly of several plys of stock in forming the multiply hoard;

Figure 2 is a perspective view of a sample of the completed product.

My improvement is leased on the discovery first that the coeficient of expansion of the paper hoard plys difiers from that of the aspheltum which is used for cementing them together. As a consequence where a plurality ofsuch plies have their adjacent faces coated with hot asphaltum and are then pressed together, the product upon cooling will warp due douhtless to the greater con traction of the asphaltum in comparison to that oi the heard. it is therefore necessary either to substitute a cement which has a. different coefiicient of expansion or one cor responding to that of the paper or to alter the expansion (or rather the contraction) of the paper plys cemented. This I have accomplished by expanding the paper through the introduction of moisture to an extent which 'is equal to the contraction in the asphaltum. Thus the moist paper plys when cemented by asphaltum will gradually contract upon loss of moisture to an extent equal to the contraction by loss of heat in the as phaltum and in this manner distortion is avoided.

As shown in detail, A, B and C are three strips of the asphaltum paper stock which are fed into contact with each other. The intermediate stri B first passes throu h a water bath D an is then fed to the r0 s E,

' E which apply hot asphaltum at a temperature of approximately 350 degrees Fahrenheit to the opposite sides of the paper. The three strips then pass together through presser rolls l which force them into intimate contact, the strips A and G being upon 9p- 7 posite sides of the strip B. Upon leavmg the rolls F the entire strip passes through a water loath G in which it remains for a suficient time for the outer layers A and G to absorb a certain amount of moisture.

Also, as the water is cold the heat from the hot asphaltum is dissipated.

The product resulting from the process just descrihed is straight when it leaves the water loath and has no tendency to warp or so distort as would he the case if the moistening step were omitted. lit is therefore my understanding that this freedom from distortion is due to the substantially equal contraction of the moistened paper and the as- $5 phaltum.

W hat ll claim as my invention is:

l. The process of forming multi-ply asphaltum paper board which consists in pass one ply off the paper through a water bath, coating both sides of this ply with hot asphaltum, feeding plys on opposite sides of the coated ply, pressing the plys together indh passing the product through a Water at i 2. The process of forming multi-ply aisphaltum board which consists in cementing a plurality of plys to each other by hot EELS- phaltum and in introducing a limited quantity of water into the outer plys subsequent to the cementing of the same.

In testimony whereof I afix my signature.

SIDNEY J. BLUM.

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